RedoxFS

這是 Redox OS 的預設檔案系統，靈感源自 ZFS，並針對微內核架構進行了調整。

Redox had a read-only ZFS driver but it was abandoned because of the monolithic nature of ZFS that created problems with the Redox microkernel design.

(It's a replacement for TFS)

Current features:

Compatible with Redox and Linux (FUSE)
寫入時複製
Data/metadata checksums
Transparent encryption
Standard Unix file attributes
File/directory size limit up to 193TiB (212TB)
File/directory quantity limit up to 4 billion per 193TiB (2^32 - 1 = 4294967295)
Disk encryption fully supported by the Redox bootloader, letting it load the kernel off an encrypted partition.
MIT licensed

Being MIT licensed, RedoxFS can be bundled on GPL-licensed operating systems (Linux, for example).

工具

RedoxFS tooling can be used to create, mount and edit contents of an .img file containing RedoxFS. It can be installed with:

cargo install redoxfs

If you found errors while installing it make sure to install the libfuse 3.x package for your Unix-like distribution.

建立磁碟

You can create an empty, non-bootable RedoxFS by allocating an empty file with fallocate then run redoxfs-mkfs to initialize the whole image as RedoxFS.

fallocate -l 1G redox.img

redoxfs-mkfs redox.img

To create an encrypted disk use the --encrypt option, it will ask the password through a masked prompt:

redoxfs-mkfs --encrypt redox.img

To create a disk with contents from an existing directory use redoxfs-ar (currently the redoxfs-ar tool overwrites existing content and have no --encrypt option).

redoxfs-ar redox.img ./sysroot

The second option of redoxfs-mkfs and third option of redoxfs-ar tools accepts a file that contains a raw image to be written as reserved disk space. This is meant to be a bootloader. Redox is booted using the official bootloader.

First you need to download the bootloader repository and build it, the following commands will build a BIOS bootloader:

git clone https://gitlab.redox-os.org/redox-os/bootloader

make -C bootloader TARGET=x86-unknown-none BUILD=build all

Once the bootloader is available at bootloader/build/bootloader.bin after compilation, you can create a new bootable disk using either redoxfs-mkfs or redoxfs-ar:

redoxfs-mkfs redox.img bootloader/build/bootloader.bin

redoxfs-ar redox.img ./sysroot bootloader/build/bootloader.bin

You can also convert a non-bootable disk into bootable using redoxfs-clone:

redoxfs-clone redox.img redox-bootable.img bootloader/build/bootloader.bin

It's not possible to create a UEFI-bootable disk using this option because it creates a GPT-partitioned disk, which currently is only implemented in redox-installer. A dual boot option in the same disk is also impossible if booting from BIOS firmware.

Note that you need to have boot/kernel and boot/initfs in the image to make it actually bootable. You can build those from the main build system or the kernel and base repositories.

掛載磁碟

To mount the disk run the redoxfs [image] [directory] command, for example:

mkdir ./redox-img

redoxfs redox.img ./redox-img

It will mount the disk using FUSE underneath.

The difference is that redoxfs-ar overwrites existing disk content. Mounting a disk through FUSE is the only way to update existing content in the RedoxFS-formatted image.

解除掛載磁碟

Unmount the disk using FUSE unmounting tool:

fusermount3 ./redox-img

擴充磁碟

⚠️ Warning: Experimental, please backup first.

To extend an existing disk, you need to extend the file before:

truncate -s 2GB redox.img

Then you can run the redoxfs-resize [disk] [size] command. The [size] option can be max (the default), min, or a fixed size defined in the parse-size library.

redoxfs-resize ./redox.img

minimum size: 438.75 MB (418.42 MiB)
maximum size: 2.00 GB (1.86 GiB)
new size: 2.00 GB (1.86 GiB)
growing by 1559135232
redoxfs-resize: resized filesystem on redox.img
	uuid: febb081e-06ff-4786-a878-f1bb031cdf97
	size: 2.00 GB (1.86 GiB)
	used: 438.65 MB (418.33 MiB)
	free: 1.56 GB (1.45 GiB)

Shrink the disk

⚠️ Warning: Experimental, please backup first.

To shrink an existing disk you can use the redoxfs-resize tool:

redoxfs-resize ./redox.img min

minimum size: 438.77 MB (418.44 MiB)
maximum size: 2.00 GB (1.86 GiB)
new size: 438.77 MB (418.44 MiB)
shrinking by 1559135232
redoxfs-resize: resized filesystem on redox.img
	uuid: febb081e-06ff-4786-a878-f1bb031cdf97
	size: 438.77 MB (418.44 MiB)
	used: 438.64 MB (418.32 MiB)
	free: 122.88 kB (120 KiB)

You can use the value from "shrinking by ..." to accurately tell how much bytes can be shrinked:

truncate -s -1559135232 redox.img

The Redox Operating System